Not all Martian spaceships need such a deep clean, scientists say


Mars-linked landers and rovers may not need to undergo such stringent clean-up procedures as before leaving Earth, a committee assessing planetary protection measures has found.

Planetary protection is the art of trying to ensure that Earth germs do not gain a foothold in other worlds and vice versa. Since the 1980s, in the name of preventing such an invasion, spacecraft have been heading to places that scientists believe are hospitable to life because we know they have to undergo rigorous cleaning procedures before taking off. But when it comes to robots going to the surface of March, NASA may be able to relax its rules, scientists explain in a 55-page report developed by the National Academies of Sciences, Engineering and Medicine at the request of NASA and published Thursday (October 7).

“The changes in planetary protection policies must be seen in the context of what science has learned in recent years about Mars,” said Amanda Hendrix, senior scientist at the Planetary Science Institute and co-chair of the committee that wrote the report. A declaration.

Related: NASA must adapt to its times in planetary protection, report says

The new report takes a deliberately narrow approach to planetary protection on Mars. The original 15 scientists are not worried about the possible arrival of terrestrial organisms. Instead, the team focused only on the possibility that terrestrial organisms could establish themselves in a way that could interfere with the search for life on Mars and the study of any life found.

There are many ways that hitchhiking terrestrial germs die on Mars, a world characterized by dramatic temperature swings, a shortage of liquid water, and an attack of ultraviolet radiation and high-energy particles called galactic cosmic rays.

“Because of this increased knowledge, NASA now has the ability to take a more nuanced and, in some cases, more permissive approach to reducing bioburden requirements for certain missions,” said Hendrix. “However, caution is always in order as we have a lot to learn about Mars and the survivability of life on Earth.”

Despite the harsh Martian environment, there are places on the Red Planet where life from Earth could take hold, the scientists wrote – for example, in a wet underground cave protected from ultraviolet rays that would burn terrestrial life on the surface of Mars. Mars’ deep surface, more than 1 meter below the surface, could also be ideal for traveling microbes seeking to survive.

With that in mind, planetary protection guidelines must continue to prevent such a scenario from occurring, the report concludes. Spacecraft venturing inside caves or drilling deep below the surface must always be ultra-clean, the scientists wrote. And these sensitive areas additionally need “buffer zones” around them to prevent terrestrial insects from reaching them accidentally or during a gust of wind.

There are other places that scientists want to be sure to keep intact, such as the ice caps at the poles of the red planet, features known as recurring slope lines which can be formed by water, and wherever methane – a chemical that has long puzzled to Mars experts – is present.

So while some spacecraft may not need to undergo such strict cleanup protocols, the guidelines for planetary protection aren’t going away anytime soon, and scientists will need to continue to assess the balance between exploring more easily. and risk disaster.

“Planetary protection measures should aim to reduce risks while preserving, as far as is reasonable, the prospect that important scientific goals can be achieved,” said Joseph Alexander, space policy consultant and committee co-chair, in the National Academies. declaration.

NASA has been debating for several years how to approach planetary protection. In 2019, an independent review committee convened by the agency published its own accounts protection of the planet, although this report has looked at the full scope, the narrow lens used by the new report.

“The planetary protection landscape is changing very rapidly,” Thomas Zurbuchen, associate administrator of NASA’s Science Missions Directorate, said in a statement. declaration at the time. “We want to be prepared in this new environment with thoughtful policies and practices that enable scientific discovery and preserve the integrity of our planet and the places we visit.”

The new report highlights the challenges of working under current planetary protection requirements, which are based on the maximum number of spores allowed. These counts are developed by adding up the number of spores on a specific section of the spacecraft, then assuming the rest of the spacecraft is similar.

Scientists on the committee note that the new techniques may better reflect the real risk, and that post-arrival activities can also help clean up the spacecraft, adding more complexity to the image of planetary protection guidelines.

The report also notes two areas in which planetary protection guidelines don’t even exist: human missions to Mars and trade missions to Mars that don’t include any NASA involvement.

Email Meghan Bartels at [email protected] or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.

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